In ancient times, priestesses at the Oracle at Delphi often answered important political questions with enigmatic predictions derived from dreams, signs, casting lots or reading animal entrails. Today, in the realm of climate change, that function is served by scientific priests and priestesses who offer forecasts of dubious value, derived from computer models.

Investing in the stock market, like planning next summer's vacation, is a dicey proposition. But if someone offered to eliminate the uncertainty – by using computer models to pick surefire investments and perfect weather windows at idyllic resorts – few would jump at the chance.

Most people know complex markets and weather defy such predictions. Computers certainly help understand and analyze these systems; they can even forecast trends, if they've been tested against actual data. However, even predicting tomorrow's IBM closing price or hurricane path is iffy, and attempts to do so months or years in advance are meaningless.

The latest example comes from Columbia University, where the Earth Institute asserts that its new "Climate Change Information Portal" will enable people to assess, avoid and adapt to "the problems that climate change and variability can cause" – and can even do so years into the future for regions as small as the tri-state New York metropolitan area. The Institute begins by assuming that human-induced global warming of alarming proportions is a fact. It then offers computer-driven guidance as to how we should respond.

Several computer models have presented "scenarios" of what might happen if temperatures really do increase 5 or 10 degrees in 100 years. These dire projections garner extensive coverage. However, the models fail miserably when tested against actual data, and there is simply no evidence to support theories of catastrophic climate change.

Indeed, satellite and weather balloon measurements have found little or no warming over the past 25 years, and other climate models project only modest warming – a degree or two over the next century. Such warming would be mostly beneficial, by bringing us longer growing seasons and lower heating bills. This kind of change people and planet can readily adapt to.

World-class geologists and climatologists emphasize that Planet Earth has been buffeted by numerous natural climate shifts for millions of years. The shifts often come in 50, 500 and 1,500-year cycles, they say.

For instance, our Earth went through a 500-year Little Ice Age – then warmed about a degree since that era ended around 1850. Nearly half of this warming occurred before 1940 – long before carbon dioxide began building up in the atmosphere. Other past climate swings also show there is little cause for alarm.

Wild weather whipsawed Detroit awhile back, according to news accounts. Six snowstorms hit during April of '68, frosts in mid-August of '69, ice in mid-May and a 98-degree heat wave in June of '74, and ice-free lakes in January of '77 and '79. But that was 1868 to 1879!

New England saw average annual temperatures increase by about 2.5 degrees F over a half century. But that was 1904-1954.

Arctic temperature increases between 1971 and 2003 might spell trouble if they continued, even though the rise was below what computer models had predicted: 1.4 degrees F per half century. However, between 1938 and 1966 average annual arctic temperaturesfell 6 degrees F. Had that trend continued, temperatures would have plummeted 10.7 degrees F in 50 years!

Moreover, the CO2 that is supposedly causing "catastrophic" warming represents only 0.00035 of all the gases in the atmosphere (1.25 inches out of a 100-yard football field), and proposals to control this vital plant nutrient ignore a far more critical greenhouse gas: water vapor.

There are at least three reasons the debate has nonetheless focused on carbon dioxide – though some are now talking about dandruff as a possible source of global warming!

CO2 is easy to measure, villainize and regulate. It would be extremely difficult to sequester water vapor, without draining the Great Lakes and turning the planet into a vast Sahara Desert . And water vapor doesn't come out of tailpipes, smokestacks and chimneys. It isn't an unwanted bastard child of the hated fossil fuel industries that radical greens want to relegate to the ash heap of history.

Certainly, human pollution and land use activities can and do affect climate. But overall that influence is minor, except sometimes locally. So we should resist calls for immediate drastic action, especially the kind that would take a wrecking ball to our economy.

Natural climate change will always be with us – driven by variations in the sun's energy output and other factors over which we have no control. For this reason, and because huge countries like China and Brazil would not be bound by their restrictions, proposals like the Kyoto Protocol would have almost no effect on future temperatures. Even treaty proponents admit that, at best, the treaty might lower the Earth's temperature by 0.1 degrees over the next half century.

That's why hardcore eco-activists now insist on a series of treaties, each one more restrictive – and more destructive – than the last. Ultimately, they would force signatory nations to slash their fossil fuel use and air emissions by up to 80 per cent over the next 50 years. But even this wouldn't stop Mother Nature.

However, it would devastate our economy, and Europe's. Manufacturing jobs would head to countries that are not governed by the treaties. Prices for gasoline, heating, air conditioning, food and consumer goods would skyrocket – hurting our poor most of all. And government tax revenues would fall precipitously, even as demand for welfare and unemployment benefits soars.

As poor countries adopt these technologies, their reliance on wood and animal dung would decline – protecting habitats and reducing pollution. They would also expand their economies, ensuring greater opportunity for their people and improved health, transportation and early warning systems that would help them avert or minimize the damage and death toll from natural disasters.

Meanwhile, we can also continue funding climate research by alarmists, skeptics and fence-sitters alike. At the very least, we may learn much more about what to expect from the next natural climate cycle – and how to adapt to the changes it will bring.

Those scary dinosaurs in Jurassic Park sure did look real. So do the frightening scenarios conjured up by outliers in the computer modeling and climate change catastrophe industries. The challenge is separating fact from probability, possibility and agenda-driven fantasy.